Smart power amplifiers (Smart PA) have been already more and more extensively applied to various terminal products at present. This sets new requirements for monitoring vibration displacement of a vibrating component (driver) of a speaker. In general, a smart PA monitors vibration displacement of a vibrating diaphragm in real time, predicts real-time displacement of the vibrating component by comparison between existing models and detected parameters, and guarantees that the vibrating component always works in a safe state.
However, there are always some deviations between physical parameters of mass-produced speakers. Under actual working conditions, vertical displacement of a vibrating system may be inconsistent. That is, there will be no guarantee of 100% consistency of the speakers. The smart PA needs to reserve enough allowance for protecting the vibrating component. At present, the maximum amplitude of the vibrating component may be influenced by the precision of detection and of the models during control of the smart PA, which predicts displacement of the vibrating component through comparison between the models and detected parameters. Consequently, original performance of the vibrating component may not be given to full play.
To solve this problem, there emerged a solution that a capacitor is formed in a speaker system to monitor real-time vibration amplitude of the speaker so as to protect the speaker in real time. However, in the prior art, a capacitance monitoring chip configured to acquire capacitance data is usually disposed outside the speaker system. The capacitor needs to be communicated with the chip outside. This leads to a relatively complicated product process design, a relatively lower degree of integration, and an undesirable real-time monitoring effect on the vibration amplitude of the speaker.
Therefore, it is necessary to put forward a technical solution in which actual displacement of the vibrating component of the speaker may be accurately monitored in real time for protecting the speaker in real time. Meanwhile, the product design process should be simplified as much as possible.